Piano-action



R. W. GERTZ.

HAND ACTION. APPLICATION FILED FEB. a, 1919.

Patented Sept. 28, 1920.

Invenfor. Richard W. Geriz y MMZLITMMI I Anya.

UNITED STATES PATENT OFFICE.

'RICHARD'W. GEBEZ, OF BBGOKLINE, MASSACHUSETTS.

PIADIO-ACTION.

Application filed February 6, 1919. Serial No. 275,283.

a a. w 710m it may concern known that l, Brennan V. Gui-1T2, izen of the United S'ates, residing at 'lrookline, county 01"- N State of Masssachusetts, have inven .11 improvement -rlctions. of which the to lowing oil .1, in connection with the accom- 1 drawing, is a, speclflcatioin like on the drawing representing r to i entioinl have illustrated in the drawing me selected embociments thereoi which will now be described. after which the novel features will be pointed out in the appended claim. 7

In the drawings, Figure l is a vertical tional view through a piano action embodying my invention;

Fig. 2 is an enlarged plan view of the flange construction;

Fig. 3 is an'enlarged sectional view on the line 33, Fig. 2; i

Fig. 4 is a plan view of the flange member illustrated in Fig. 2;

Fig. 5 is a'plan View member shown in Fig. 2;

Fig. 6 is a view showing a modified form of the invention taken on the line 6-6, Fig. 7

Fig. 7 is a plan view of the flange shown in Fig. 6.

In the drawings, 1 indicates a portion of the key frame of a grand piano on which the keys 2 are pivoted and 3 indicates one of the action brackets which support the rails l and 5 that carry the flanges to which the hammer shanks 6 and wipgens 7 are usually pivoted. Each wippen 7 is of usual construction and embodies a repetition lever 8 which cooperates with a stop screw 36.

These parts are or may be all as usual in grand piano actions and hence need no further description.

In my invention the flanges to which the hammer shanks 6 are pivoted are made of metal and each support a stop screw 36. In order that the piano action may operate properly, it is, of course, necessary that the stop screws 36 should maintain their proper adjustment, for if any stop-screw loses its adjustment the piano action will not operof the retaining I I .rrom becoming loosened.

ate properly. I have provided herein a novel construction of metal flange which is provided with means for locking the stop screw 36 and thus preventing it from becoming loosened or losing its adjustment.

In the const uction shown in Figs. 1 and 3, the flange member to which the hammer shank is pivoted is shown at 10 and it is in the nature of a small metal plate which rests on the top surface 11 of the rail 4: and fits at one end against the lip 12 thereof. Said flange member is clamped to the rail by means of a clamping screw 27. The other end of the flange projects beyond the rail and is provided with the tongue 13 which enters between the arms 14 of the forked end of the hammer shank 6 and is provided with a groove 15 in which is received the pivot pin 16 by which the hammer shank is pivoted to the flange member. The pivot pin is fixedly clamped to the tongue 13 by means of a clamping plate or retaining member 17 which is clamped to said tongue by the clamping screw 37.

In order to lock the stop-screw 36 I provide the flange 10 with slit 98 which intersects the screw-threaded aperture 97 through which the screw 36 passes. The aperture 97 is'made with a slightly smaller diameter than that of the stop screw 36 so that when the stop screw is screw-threaded into the aperture said aperture is expanded or spread somewhat, thus producing a binding pressure on the top screw which prevents it The slit 98 is shown as extending to the screw-threaded aperture into which the clamping screw 37 is screw-threaded The retaining member 17 is formed at its rear end with an enlarged aperture 94 through which the stop screw extends. said aperture being of suflicient diameter so that it does not engage the screw threads of the stop screw. The retaining member is shown as provided with suitable ribs 95 for the purpose of strengthening it. The flange member 10 is shown as provided with a narrow or necked portion 93 immediately back of the slit 98 and the sides of said necked portion are bounded by vertical flanges 92. The purpose of this necked portion is to accommodate a spanner or other tool which may be used for bending or adjusting the flange member'so as to bring the hammer shank to which it is attached into proper alinement.

In Figs. 6 and 7, I have shown a difii'erent construction in which the flange member indicated at 100 is formed with an enlarged aperture 88 immediately in front of the rail 4 through which an implement may be in serted for the purpose of bending the flange to bring the hammer shank into proper 'alinement. In'thisconstruction also the slit 98 is eliminated and the stop screw 36 is screw-threaded through both the flange and the clamping or retaining plate which is inv dicated, at 170. By thus screw-threading the stop screw through both the flange and the retaining member, said step screw is locked from turning movement.

It will be noted that the rear end of the clamping member is separated slightly from the flange, and hence when the clamping screw 87'is tightened, the downward pressure or" said clampingv screw will produce a downward pressure atthe rear end of the retaining member so that the retaining member acts as .a nut-lock for preventing the clamping screw from loosening. 1 o

" ,7 It will be noted that in both embodiments of my invention the means for locking the stop-screw 36 is entirely separate and inde-,,

pendent from the clamping screw 27 by which the flange is clamped to the rail so that any stop screw'may beadjusted if necessary without loosening the flange from the trail and W h losing the adjustment which has been given tofthe'flange; This highly, advantageous because after any flange has once been secured on the rail and properly adjusted so that the corresponding hammer shank will be in perfect alinement, it is important that this adjustment should be maintained, for if the position of the flange is disturbed, then the hammer will not be perfectly alined and the toneof the:

piano will be thereby impaired. I claim: 7 V i V r In a piano action, the combination with a supporting rail, of a flange member supported thereon and having a transverse groove, means for securing the flange memher tothe supporting rail, a pivot pin in {said groove, a hammer shank pivotally connected to said pivot pin, a clamping'memher for retaining the pivot pin in the groove,

j ln' testimony whereof, I have signed my name to this specification.

Eleni), w. e Rrz.

'tition lever screwsthreaded through the means for securing the clamping member 

